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.\" Copyright (c) 2020-2022 by Alejandro Colomar <alx@kernel.org>
.\" and Copyright (c) 2020 by Michael Kerrisk <mtk.manpages@gmail.com>
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.\"
.TH double_t 3type 2022-12-15 "Linux man-pages 6.03"
.SH NAME
float_t, double_t \- most efficient floating types
.SH LIBRARY
Math library
.RI ( libm )
.SH SYNOPSIS
.nf
.B #include <math.h>
.PP
.BR typedef " /* ... */ " float_t;
.BR typedef " /* ... */ " double_t;
.fi
.SH DESCRIPTION
The implementation's most efficient floating types at least as wide as
.I float
and
.I double
respectively.
Their type depends on the value of the macro
.B FLT_EVAL_METHOD
(defined in
.IR <float.h> ):
.PP
.TS
lB rI rI.
FLT_EVAL_METHOD	float_t	double_t
.T&
n rI rI.
_
0	float	double
1	double	double
2	long double	long double
.TE
.PP
For other values of
.BR FLT_EVAL_METHOD ,
the types of
.I float_t
and
.I double_t
are implementation-defined.
.SH STANDARDS
C99 and later; POSIX.1-2001 and later.
.SH SEE ALSO
.BR float.h (0p),
.BR math.h (0p)
